xref: /original-bsd/sys/sys/vnode.h (revision f737e041)
1 /*
2  * Copyright (c) 1989, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * %sccs.include.redist.c%
6  *
7  *	@(#)vnode.h	8.7 (Berkeley) 02/04/94
8  */
9 
10 #include <sys/queue.h>
11 
12 /*
13  * The vnode is the focus of all file activity in UNIX.  There is a
14  * unique vnode allocated for each active file, each current directory,
15  * each mounted-on file, text file, and the root.
16  */
17 
18 /*
19  * Vnode types.  VNON means no type.
20  */
21 enum vtype	{ VNON, VREG, VDIR, VBLK, VCHR, VLNK, VSOCK, VFIFO, VBAD };
22 
23 /*
24  * Vnode tag types.
25  * These are for the benefit of external programs only (e.g., pstat)
26  * and should NEVER be inspected by the kernel.
27  */
28 enum vtagtype	{
29 	VT_NON, VT_UFS, VT_NFS, VT_MFS, VT_PC, VT_LFS, VT_LOFS, VT_FDESC,
30 	VT_PORTAL, VT_NULL, VT_UMAP, VT_KERNFS, VT_PROCFS, VT_AFS, VT_ISOFS,
31 	VT_UNION
32 };
33 
34 /*
35  * Each underlying filesystem allocates its own private area and hangs
36  * it from v_data.  If non-null, this area is freed in getnewvnode().
37  */
38 LIST_HEAD(buflists, buf);
39 
40 struct vnode {
41 	u_long	v_flag;				/* vnode flags (see below) */
42 	short	v_usecount;			/* reference count of users */
43 	short	v_writecount;			/* reference count of writers */
44 	long	v_holdcnt;			/* page & buffer references */
45 	daddr_t	v_lastr;			/* last read (read-ahead) */
46 	u_long	v_id;				/* capability identifier */
47 	struct	mount *v_mount;			/* ptr to vfs we are in */
48 	int 	(**v_op)();			/* vnode operations vector */
49 	TAILQ_ENTRY(vnode) v_freelist;		/* vnode freelist */
50 	LIST_ENTRY(vnode) v_mntvnodes;		/* vnodes for mount point */
51 	struct	buflists v_cleanblkhd;		/* clean blocklist head */
52 	struct	buflists v_dirtyblkhd;		/* dirty blocklist head */
53 	long	v_numoutput;			/* num of writes in progress */
54 	enum	vtype v_type;			/* vnode type */
55 	union {
56 		struct mount	*vu_mountedhere;/* ptr to mounted vfs (VDIR) */
57 		struct socket	*vu_socket;	/* unix ipc (VSOCK) */
58 		caddr_t		vu_vmdata;	/* private data for vm (VREG) */
59 		struct specinfo	*vu_specinfo;	/* device (VCHR, VBLK) */
60 		struct fifoinfo	*vu_fifoinfo;	/* fifo (VFIFO) */
61 	} v_un;
62 	struct	nqlease *v_lease;		/* Soft reference to lease */
63 	daddr_t	v_lastw;			/* last write (write cluster) */
64 	daddr_t	v_cstart;			/* start block of cluster */
65 	daddr_t	v_lasta;			/* last allocation */
66 	int	v_clen;				/* length of current cluster */
67 	int	v_ralen;			/* Read-ahead length */
68 	daddr_t	v_maxra;			/* last readahead block */
69 	long	v_spare[7];			/* round to 128 bytes */
70 	enum	vtagtype v_tag;			/* type of underlying data */
71 	void 	*v_data;			/* private data for fs */
72 };
73 #define	v_mountedhere	v_un.vu_mountedhere
74 #define	v_socket	v_un.vu_socket
75 #define	v_vmdata	v_un.vu_vmdata
76 #define	v_specinfo	v_un.vu_specinfo
77 #define	v_fifoinfo	v_un.vu_fifoinfo
78 
79 /*
80  * Vnode flags.
81  */
82 #define	VROOT		0x0001	/* root of its file system */
83 #define	VTEXT		0x0002	/* vnode is a pure text prototype */
84 #define	VSYSTEM		0x0004	/* vnode being used by kernel */
85 #define	VXLOCK		0x0100	/* vnode is locked to change underlying type */
86 #define	VXWANT		0x0200	/* process is waiting for vnode */
87 #define	VBWAIT		0x0400	/* waiting for output to complete */
88 #define	VALIASED	0x0800	/* vnode has an alias */
89 #define	VDIROP		0x1000	/* LFS: vnode is involved in a directory op */
90 
91 /*
92  * Vnode attributes.  A field value of VNOVAL represents a field whose value
93  * is unavailable (getattr) or which is not to be changed (setattr).
94  */
95 struct vattr {
96 	enum vtype	va_type;	/* vnode type (for create) */
97 	u_short		va_mode;	/* files access mode and type */
98 	short		va_nlink;	/* number of references to file */
99 	uid_t		va_uid;		/* owner user id */
100 	gid_t		va_gid;		/* owner group id */
101 	long		va_fsid;	/* file system id (dev for now) */
102 	long		va_fileid;	/* file id */
103 	u_quad_t	va_size;	/* file size in bytes */
104 	long		va_blocksize;	/* blocksize preferred for i/o */
105 	struct timespec	va_atime;	/* time of last access */
106 	struct timespec	va_mtime;	/* time of last modification */
107 	struct timespec	va_ctime;	/* time file changed */
108 	u_long		va_gen;		/* generation number of file */
109 	u_long		va_flags;	/* flags defined for file */
110 	dev_t		va_rdev;	/* device the special file represents */
111 	u_quad_t	va_bytes;	/* bytes of disk space held by file */
112 	u_quad_t	va_filerev;	/* file modification number */
113 	u_int		va_vaflags;	/* operations flags, see below */
114 	long		va_spare;	/* remain quad aligned */
115 };
116 
117 /*
118  * Flags for va_cflags.
119  */
120 #define	VA_UTIMES_NULL	0x01		/* utimes argument was NULL */
121 
122 /*
123  * Flags for ioflag.
124  */
125 #define	IO_UNIT		0x01		/* do I/O as atomic unit */
126 #define	IO_APPEND	0x02		/* append write to end */
127 #define	IO_SYNC		0x04		/* do I/O synchronously */
128 #define	IO_NODELOCKED	0x08		/* underlying node already locked */
129 #define	IO_NDELAY	0x10		/* FNDELAY flag set in file table */
130 
131 /*
132  *  Modes.  Some values same as Ixxx entries from inode.h for now.
133  */
134 #define	VSUID	04000		/* set user id on execution */
135 #define	VSGID	02000		/* set group id on execution */
136 #define	VSVTX	01000		/* save swapped text even after use */
137 #define	VREAD	00400		/* read, write, execute permissions */
138 #define	VWRITE	00200
139 #define	VEXEC	00100
140 
141 /*
142  * Token indicating no attribute value yet assigned.
143  */
144 #define	VNOVAL	(-1)
145 
146 #ifdef KERNEL
147 /*
148  * Convert between vnode types and inode formats (since POSIX.1
149  * defines mode word of stat structure in terms of inode formats).
150  */
151 extern enum vtype	iftovt_tab[];
152 extern int		vttoif_tab[];
153 #define IFTOVT(mode)	(iftovt_tab[((mode) & S_IFMT) >> 12])
154 #define VTTOIF(indx)	(vttoif_tab[(int)(indx)])
155 #define MAKEIMODE(indx, mode)	(int)(VTTOIF(indx) | (mode))
156 
157 /*
158  * Flags to various vnode functions.
159  */
160 #define	SKIPSYSTEM	0x0001		/* vflush: skip vnodes marked VSYSTEM */
161 #define	FORCECLOSE	0x0002		/* vflush: force file closeure */
162 #define	WRITECLOSE	0x0004		/* vflush: only close writeable files */
163 #define	DOCLOSE		0x0008		/* vclean: close active files */
164 #define	V_SAVE		0x0001		/* vinvalbuf: sync file first */
165 #define	V_SAVEMETA	0x0002		/* vinvalbuf: leave indirect blocks */
166 
167 #ifdef DIAGNOSTIC
168 #define	HOLDRELE(vp)	holdrele(vp)
169 #define	VATTR_NULL(vap)	vattr_null(vap)
170 #define	VHOLD(vp)	vhold(vp)
171 #define	VREF(vp)	vref(vp)
172 
173 void	holdrele __P((struct vnode *));
174 void	vattr_null __P((struct vattr *));
175 void	vhold __P((struct vnode *));
176 void	vref __P((struct vnode *));
177 #else
178 #define	HOLDRELE(vp)	(vp)->v_holdcnt--	/* decrease buf or page ref */
179 #define	VATTR_NULL(vap)	(*(vap) = va_null)	/* initialize a vattr */
180 #define	VHOLD(vp)	(vp)->v_holdcnt++	/* increase buf or page ref */
181 #define	VREF(vp)	(vp)->v_usecount++	/* increase reference */
182 #endif
183 
184 #define	NULLVP	((struct vnode *)NULL)
185 
186 /*
187  * Global vnode data.
188  */
189 extern	struct vnode *rootvnode;	/* root (i.e. "/") vnode */
190 extern	int desiredvnodes;		/* number of vnodes desired */
191 extern	struct vattr va_null;		/* predefined null vattr structure */
192 
193 /*
194  * Macro/function to check for client cache inconsistency w.r.t. leasing.
195  */
196 #define	LEASE_READ	0x1		/* Check lease for readers */
197 #define	LEASE_WRITE	0x2		/* Check lease for modifiers */
198 
199 #ifdef NFS
200 void	lease_check __P((struct vnode *vp, struct proc *p,
201 	    struct ucred *ucred, int flag));
202 void	lease_updatetime __P((int deltat));
203 #define	LEASE_CHECK(vp, p, cred, flag)	lease_check((vp), (p), (cred), (flag))
204 #define	LEASE_UPDATETIME(dt)		lease_updatetime(dt)
205 #else
206 #define	LEASE_CHECK(vp, p, cred, flag)
207 #define	LEASE_UPDATETIME(dt)
208 #endif /* NFS */
209 #endif /* KERNEL */
210 
211 
212 /*
213  * Mods for exensibility.
214  */
215 
216 /*
217  * Flags for vdesc_flags:
218  */
219 #define VDESC_MAX_VPS		16
220 /* Low order 16 flag bits are reserved for willrele flags for vp arguments. */
221 #define VDESC_VP0_WILLRELE	0x0001
222 #define VDESC_VP1_WILLRELE	0x0002
223 #define VDESC_VP2_WILLRELE	0x0004
224 #define VDESC_VP3_WILLRELE	0x0008
225 #define VDESC_NOMAP_VPP		0x0100
226 #define VDESC_VPP_WILLRELE	0x0200
227 
228 /*
229  * VDESC_NO_OFFSET is used to identify the end of the offset list
230  * and in places where no such field exists.
231  */
232 #define VDESC_NO_OFFSET -1
233 
234 /*
235  * This structure describes the vnode operation taking place.
236  */
237 struct vnodeop_desc {
238 	int	vdesc_offset;		/* offset in vector--first for speed */
239 	char    *vdesc_name;		/* a readable name for debugging */
240 	int	vdesc_flags;		/* VDESC_* flags */
241 
242 	/*
243 	 * These ops are used by bypass routines to map and locate arguments.
244 	 * Creds and procs are not needed in bypass routines, but sometimes
245 	 * they are useful to (for example) transport layers.
246 	 * Nameidata is useful because it has a cred in it.
247 	 */
248 	int	*vdesc_vp_offsets;	/* list ended by VDESC_NO_OFFSET */
249 	int	vdesc_vpp_offset;	/* return vpp location */
250 	int	vdesc_cred_offset;	/* cred location, if any */
251 	int	vdesc_proc_offset;	/* proc location, if any */
252 	int	vdesc_componentname_offset; /* if any */
253 	/*
254 	 * Finally, we've got a list of private data (about each operation)
255 	 * for each transport layer.  (Support to manage this list is not
256 	 * yet part of BSD.)
257 	 */
258 	caddr_t	*vdesc_transports;
259 };
260 
261 #ifdef KERNEL
262 /*
263  * A list of all the operation descs.
264  */
265 extern struct vnodeop_desc *vnodeop_descs[];
266 
267 
268 /*
269  * This macro is very helpful in defining those offsets in the vdesc struct.
270  *
271  * This is stolen from X11R4.  I ingored all the fancy stuff for
272  * Crays, so if you decide to port this to such a serious machine,
273  * you might want to consult Intrisics.h's XtOffset{,Of,To}.
274  */
275 #define VOPARG_OFFSET(p_type,field) \
276         ((int) (((char *) (&(((p_type)NULL)->field))) - ((char *) NULL)))
277 #define VOPARG_OFFSETOF(s_type,field) \
278 	VOPARG_OFFSET(s_type*,field)
279 #define VOPARG_OFFSETTO(S_TYPE,S_OFFSET,STRUCT_P) \
280 	((S_TYPE)(((char*)(STRUCT_P))+(S_OFFSET)))
281 
282 
283 /*
284  * This structure is used to configure the new vnodeops vector.
285  */
286 struct vnodeopv_entry_desc {
287 	struct vnodeop_desc *opve_op;   /* which operation this is */
288 	int (*opve_impl)();		/* code implementing this operation */
289 };
290 struct vnodeopv_desc {
291 			/* ptr to the ptr to the vector where op should go */
292 	int (***opv_desc_vector_p)();
293 	struct vnodeopv_entry_desc *opv_desc_ops;   /* null terminated list */
294 };
295 
296 /*
297  * A default routine which just returns an error.
298  */
299 int vn_default_error __P((void));
300 
301 /*
302  * A generic structure.
303  * This can be used by bypass routines to identify generic arguments.
304  */
305 struct vop_generic_args {
306 	struct vnodeop_desc *a_desc;
307 	/* other random data follows, presumably */
308 };
309 
310 /*
311  * VOCALL calls an op given an ops vector.  We break it out because BSD's
312  * vclean changes the ops vector and then wants to call ops with the old
313  * vector.
314  */
315 #define VOCALL(OPSV,OFF,AP) (( *((OPSV)[(OFF)])) (AP))
316 
317 /*
318  * This call works for vnodes in the kernel.
319  */
320 #define VCALL(VP,OFF,AP) VOCALL((VP)->v_op,(OFF),(AP))
321 #define VDESC(OP) (& __CONCAT(OP,_desc))
322 #define VOFFSET(OP) (VDESC(OP)->vdesc_offset)
323 
324 /*
325  * Finally, include the default set of vnode operations.
326  */
327 #include <vnode_if.h>
328 
329 /*
330  * Public vnode manipulation functions.
331  */
332 struct file;
333 struct mount;
334 struct nameidata;
335 struct proc;
336 struct stat;
337 struct ucred;
338 struct uio;
339 struct vattr;
340 struct vnode;
341 struct vop_bwrite_args;
342 
343 int 	bdevvp __P((dev_t dev, struct vnode **vpp));
344 int 	getnewvnode __P((enum vtagtype tag,
345 	    struct mount *mp, int (**vops)(), struct vnode **vpp));
346 int	vinvalbuf __P((struct vnode *vp, int save, struct ucred *cred,
347 	    struct proc *p, int slpflag, int slptimeo));
348 void 	vattr_null __P((struct vattr *vap));
349 int 	vcount __P((struct vnode *vp));
350 int 	vget __P((struct vnode *vp, int lockflag));
351 void 	vgone __P((struct vnode *vp));
352 void 	vgoneall __P((struct vnode *vp));
353 int	vn_bwrite __P((struct vop_bwrite_args *ap));
354 int 	vn_close __P((struct vnode *vp,
355 	    int flags, struct ucred *cred, struct proc *p));
356 int 	vn_closefile __P((struct file *fp, struct proc *p));
357 int	vn_ioctl __P((struct file *fp, int com, caddr_t data, struct proc *p));
358 int 	vn_open __P((struct nameidata *ndp, int fmode, int cmode));
359 int 	vn_rdwr __P((enum uio_rw rw, struct vnode *vp, caddr_t base,
360 	    int len, off_t offset, enum uio_seg segflg, int ioflg,
361 	    struct ucred *cred, int *aresid, struct proc *p));
362 int	vn_read __P((struct file *fp, struct uio *uio, struct ucred *cred));
363 int	vn_select __P((struct file *fp, int which, struct proc *p));
364 int	vn_stat __P((struct vnode *vp, struct stat *sb, struct proc *p));
365 int	vn_write __P((struct file *fp, struct uio *uio, struct ucred *cred));
366 struct vnode *
367 	checkalias __P((struct vnode *vp, dev_t nvp_rdev, struct mount *mp));
368 void 	vput __P((struct vnode *vp));
369 void 	vref __P((struct vnode *vp));
370 void 	vrele __P((struct vnode *vp));
371 #endif /* KERNEL */
372