xref: /original-bsd/sys/sys/vnode.h (revision 874499c7)
1 /*
2  * Copyright (c) 1989 The Regents of the University of California.
3  * All rights reserved.
4  *
5  * %sccs.include.redist.c%
6  *
7  *	@(#)vnode.h	7.68 (Berkeley) 03/19/93
8  */
9 
10 #ifndef KERNEL
11 #include <machine/endian.h>
12 #endif
13 #include <sys/queue.h>
14 
15 /*
16  * The vnode is the focus of all file activity in UNIX.  There is a
17  * unique vnode allocated for each active file, each current directory,
18  * each mounted-on file, text file, and the root.
19  */
20 
21 /*
22  * Vnode types.  VNON means no type.
23  */
24 enum vtype	{ VNON, VREG, VDIR, VBLK, VCHR, VLNK, VSOCK, VFIFO, VBAD };
25 
26 /*
27  * Vnode tag types.
28  * These are for the benefit of external programs only (e.g., pstat)
29  * and should NEVER be inspected by the kernel.
30  */
31 enum vtagtype	{ VT_NON, VT_UFS, VT_NFS, VT_MFS, VT_LFS };
32 
33 /*
34  * Each underlying filesystem allocates its own private area and hangs
35  * it from v_data.  If non-null, this area is free in getnewvnode().
36  */
37 struct vnode {
38 	u_long	v_flag;				/* vnode flags (see below) */
39 	short	v_usecount;			/* reference count of users */
40 	short	v_writecount;			/* reference count of writers */
41 	long	v_holdcnt;			/* page & buffer references */
42 	daddr_t	v_lastr;			/* last read (read-ahead) */
43 	u_long	v_id;				/* capability identifier */
44 	struct	mount *v_mount;			/* ptr to vfs we are in */
45 	int 	(**v_op)();			/* vnode operations vector */
46 	struct	vnode *v_freef;			/* vnode freelist forward */
47 	struct	vnode **v_freeb;		/* vnode freelist back */
48 	struct	vnode *v_mountf;		/* vnode mountlist forward */
49 	struct	vnode **v_mountb;		/* vnode mountlist back */
50 	struct	list_entry v_cleanblkhd;	/* clean blocklist head */
51 	struct	list_entry v_dirtyblkhd;	/* dirty blocklist head */
52 	long	v_numoutput;			/* num of writes in progress */
53 	enum	vtype v_type;			/* vnode type */
54 	union {
55 		struct mount	*vu_mountedhere;/* ptr to mounted vfs (VDIR) */
56 		struct socket	*vu_socket;	/* unix ipc (VSOCK) */
57 		caddr_t		vu_vmdata;	/* private data for vm (VREG) */
58 		struct specinfo	*vu_specinfo;	/* device (VCHR, VBLK) */
59 		struct fifoinfo	*vu_fifoinfo;	/* fifo (VFIFO) */
60 	} v_un;
61 	struct	nqlease *v_lease;		/* Soft reference to lease */
62 	daddr_t	v_lastw;			/* last write (write cluster) */
63 	daddr_t	v_cstart;			/* start block of cluster */
64 	daddr_t	v_lasta;			/* last allocation */
65 	int	v_clen;				/* length of current cluster */
66 	int	v_ralen;			/* Read-ahead length */
67 	long	v_spare[8];			/* round to 128 bytes */
68 	enum	vtagtype v_tag;			/* type of underlying data */
69 	void 	*v_data;			/* private data for fs */
70 };
71 #define	v_mountedhere	v_un.vu_mountedhere
72 #define	v_socket	v_un.vu_socket
73 #define	v_vmdata	v_un.vu_vmdata
74 #define	v_specinfo	v_un.vu_specinfo
75 #define	v_fifoinfo	v_un.vu_fifoinfo
76 
77 /*
78  * Vnode flags.
79  */
80 #define	VROOT		0x0001	/* root of its file system */
81 #define	VTEXT		0x0002	/* vnode is a pure text prototype */
82 #define	VSYSTEM		0x0004	/* vnode being used by kernel */
83 #define	VXLOCK		0x0100	/* vnode is locked to change underlying type */
84 #define	VXWANT		0x0200	/* process is waiting for vnode */
85 #define	VBWAIT		0x0400	/* waiting for output to complete */
86 #define	VALIASED	0x0800	/* vnode has an alias */
87 #define	VDIROP		0x1000	/* LFS: vnode is involved in a directory op */
88 
89 /*
90  * Vnode attributes.  A field value of VNOVAL represents a field whose value
91  * is unavailable (getattr) or which is not to be changed (setattr).
92  */
93 struct vattr {
94 	enum vtype	va_type;	/* vnode type (for create) */
95 	u_short		va_mode;	/* files access mode and type */
96 	short		va_nlink;	/* number of references to file */
97 	uid_t		va_uid;		/* owner user id */
98 	gid_t		va_gid;		/* owner group id */
99 	long		va_fsid;	/* file system id (dev for now) */
100 	long		va_fileid;	/* file id */
101 	u_quad_t	va_size;	/* file size in bytes */
102 	long		va_blocksize;	/* blocksize preferred for i/o */
103 	struct timespec	va_atime;	/* time of last access */
104 	struct timespec	va_mtime;	/* time of last modification */
105 	struct timespec	va_ctime;	/* time file changed */
106 	u_long		va_gen;		/* generation number of file */
107 	u_long		va_flags;	/* flags defined for file */
108 	dev_t		va_rdev;	/* device the special file represents */
109 	u_quad_t	va_bytes;	/* bytes of disk space held by file */
110 	u_quad_t	va_filerev;	/* file modification number */
111 	u_int		va_vaflags;	/* operations flags, see below */
112 	long		va_spare;	/* remain quad aligned */
113 };
114 
115 /*
116  * Flags for va_cflags.
117  */
118 #define	VA_UTIMES_NULL	0x01		/* utimes argument was NULL */
119 
120 /*
121  * Flags for ioflag.
122  */
123 #define	IO_UNIT		0x01		/* do I/O as atomic unit */
124 #define	IO_APPEND	0x02		/* append write to end */
125 #define	IO_SYNC		0x04		/* do I/O synchronously */
126 #define	IO_NODELOCKED	0x08		/* underlying node already locked */
127 #define	IO_NDELAY	0x10		/* FNDELAY flag set in file table */
128 
129 /*
130  *  Modes.  Some values same as Ixxx entries from inode.h for now.
131  */
132 #define	VSUID	04000		/* set user id on execution */
133 #define	VSGID	02000		/* set group id on execution */
134 #define	VSVTX	01000		/* save swapped text even after use */
135 #define	VREAD	00400		/* read, write, execute permissions */
136 #define	VWRITE	00200
137 #define	VEXEC	00100
138 
139 /*
140  * Token indicating no attribute value yet assigned.
141  */
142 #define	VNOVAL	(-1)
143 
144 #ifdef KERNEL
145 /*
146  * Convert between vnode types and inode formats (since POSIX.1
147  * defines mode word of stat structure in terms of inode formats).
148  */
149 extern enum vtype	iftovt_tab[];
150 extern int		vttoif_tab[];
151 #define IFTOVT(mode)	(iftovt_tab[((mode) & S_IFMT) >> 12])
152 #define VTTOIF(indx)	(vttoif_tab[(int)(indx)])
153 #define MAKEIMODE(indx, mode)	(int)(VTTOIF(indx) | (mode))
154 
155 /*
156  * Flags to various vnode functions.
157  */
158 #define	SKIPSYSTEM	0x0001		/* vflush: skip vnodes marked VSYSTEM */
159 #define	FORCECLOSE	0x0002		/* vflush: force file closeure */
160 #define	WRITECLOSE	0x0004		/* vflush: only close writeable files */
161 #define	DOCLOSE		0x0008		/* vclean: close active files */
162 #define	V_SAVE		0x0001		/* vinvalbuf: sync file first */
163 #define	V_SAVEMETA	0x0002		/* vinvalbuf: leave indirect blocks */
164 
165 #ifdef DIAGNOSTIC
166 #define	HOLDRELE(vp)	holdrele(vp)
167 #define	VATTR_NULL(vap)	vattr_null(vap)
168 #define	VHOLD(vp)	vhold(vp)
169 #define	VREF(vp)	vref(vp)
170 
171 void	holdrele __P((struct vnode *));
172 void	vattr_null __P((struct vattr *));
173 void	vhold __P((struct vnode *));
174 void	vref __P((struct vnode *));
175 #else
176 #define	HOLDRELE(vp)	(vp)->v_holdcnt--	/* decrease buf or page ref */
177 #define	VATTR_NULL(vap)	(*(vap) = va_null)	/* initialize a vattr */
178 #define	VHOLD(vp)	(vp)->v_holdcnt++	/* increase buf or page ref */
179 #define	VREF(vp)	(vp)->v_usecount++	/* increase reference */
180 #endif
181 
182 #define	NULLVP	((struct vnode *)NULL)
183 
184 /*
185  * Global vnode data.
186  */
187 extern	struct vnode *rootdir;		/* root (i.e. "/") vnode */
188 extern	int desiredvnodes;		/* number of vnodes desired */
189 extern	struct vattr va_null;		/* predefined null vattr structure */
190 
191 /*
192  * Macro/function to check for client cache inconsistency w.r.t. leasing.
193  */
194 #define	LEASE_READ	0x1		/* Check lease for readers */
195 #define	LEASE_WRITE	0x2		/* Check lease for modifiers */
196 
197 #ifdef NFS
198 void	lease_check __P((struct vnode *vp, struct proc *p,
199 	    struct ucred *ucred, int flag));
200 void	lease_updatetime __P((int deltat));
201 #define	LEASE_CHECK(vp, p, cred, flag)	lease_check((vp), (p), (cred), (flag))
202 #define	LEASE_UPDATETIME(dt)		lease_updatetime(dt)
203 #else
204 #define	LEASE_CHECK(vp, p, cred, flag)
205 #define	LEASE_UPDATETIME(dt)
206 #endif /* NFS */
207 #endif /* KERNEL */
208 
209 
210 /*
211  * Mods for exensibility.
212  */
213 
214 /*
215  * Flags for vdesc_flags:
216  */
217 #define VDESC_MAX_VPS		16
218 /* Low order 16 flag bits are reserved for willrele flags for vp arguments. */
219 #define VDESC_VP0_WILLRELE	0x0001
220 #define VDESC_VP1_WILLRELE	0x0002
221 #define VDESC_VP2_WILLRELE	0x0004
222 #define VDESC_VP3_WILLRELE	0x0008
223 #define VDESC_NOMAP_VPP		0x0100
224 #define VDESC_VPP_WILLRELE	0x0200
225 
226 /*
227  * VDESC_NO_OFFSET is used to identify the end of the offset list
228  * and in places where no such field exists.
229  */
230 #define VDESC_NO_OFFSET -1
231 
232 /*
233  * This structure describes the vnode operation taking place.
234  */
235 struct vnodeop_desc {
236 	int	vdesc_offset;		/* offset in vector--first for speed */
237 	char    *vdesc_name;		/* a readable name for debugging */
238 	int	vdesc_flags;		/* VDESC_* flags */
239 
240 	/*
241 	 * These ops are used by bypass routines to map and locate arguments.
242 	 * Creds and procs are not needed in bypass routines, but sometimes
243 	 * they are useful to (for example) transport layers.
244 	 * Nameidata is useful because it has a cred in it.
245 	 */
246 	int	*vdesc_vp_offsets;	/* list ended by VDESC_NO_OFFSET */
247 	int	vdesc_vpp_offset;	/* return vpp location */
248 	int	vdesc_cred_offset;	/* cred location, if any */
249 	int	vdesc_proc_offset;	/* proc location, if any */
250 	int	vdesc_componentname_offset; /* if any */
251 	/*
252 	 * Finally, we've got a list of private data (about each operation)
253 	 * for each transport layer.  (Support to manage this list is not
254 	 * yet part of BSD.)
255 	 */
256 	caddr_t	*vdesc_transports;
257 };
258 
259 #ifdef KERNEL
260 /*
261  * A list of all the operation descs.
262  */
263 extern struct vnodeop_desc *vnodeop_descs[];
264 
265 
266 /*
267  * This macro is very helpful in defining those offsets in the vdesc struct.
268  *
269  * This is stolen from X11R4.  I ingored all the fancy stuff for
270  * Crays, so if you decide to port this to such a serious machine,
271  * you might want to consult Intrisics.h's XtOffset{,Of,To}.
272  */
273 #define VOPARG_OFFSET(p_type,field) \
274         ((int) (((char *) (&(((p_type)NULL)->field))) - ((char *) NULL)))
275 #define VOPARG_OFFSETOF(s_type,field) \
276 	VOPARG_OFFSET(s_type*,field)
277 #define VOPARG_OFFSETTO(S_TYPE,S_OFFSET,STRUCT_P) \
278 	((S_TYPE)(((char*)(STRUCT_P))+(S_OFFSET)))
279 
280 
281 /*
282  * This structure is used to configure the new vnodeops vector.
283  */
284 struct vnodeopv_entry_desc {
285 	struct vnodeop_desc *opve_op;   /* which operation this is */
286 	int (*opve_impl)();		/* code implementing this operation */
287 };
288 struct vnodeopv_desc {
289 			/* ptr to the ptr to the vector where op should go */
290 	int (***opv_desc_vector_p)();
291 	struct vnodeopv_entry_desc *opv_desc_ops;   /* null terminated list */
292 };
293 
294 /*
295  * A default routine which just returns an error.
296  */
297 int vn_default_error __P((void));
298 
299 /*
300  * A generic structure.
301  * This can be used by bypass routines to identify generic arguments.
302  */
303 struct vop_generic_args {
304 	struct vnodeop_desc *a_desc;
305 	/* other random data follows, presumably */
306 };
307 
308 /*
309  * VOCALL calls an op given an ops vector.  We break it out because BSD's
310  * vclean changes the ops vector and then wants to call ops with the old
311  * vector.
312  */
313 #define VOCALL(OPSV,OFF,AP) (( *((OPSV)[(OFF)])) (AP))
314 
315 /*
316  * This call works for vnodes in the kernel.
317  */
318 #define VCALL(VP,OFF,AP) VOCALL((VP)->v_op,(OFF),(AP))
319 #define VDESC(OP) (& __CONCAT(OP,_desc))
320 #define VOFFSET(OP) (VDESC(OP)->vdesc_offset)
321 
322 /*
323  * Finally, include the default set of vnode operations.
324  */
325 #include <vnode_if.h>
326 
327 /*
328  * Public vnode manipulation functions.
329  */
330 struct file;
331 struct mount;
332 struct nameidata;
333 struct proc;
334 struct stat;
335 struct ucred;
336 struct uio;
337 struct vattr;
338 struct vnode;
339 struct vop_bwrite_args;
340 
341 int 	bdevvp __P((dev_t dev, struct vnode **vpp));
342 int 	getnewvnode __P((enum vtagtype tag,
343 	    struct mount *mp, int (**vops)(), struct vnode **vpp));
344 int	vinvalbuf __P((struct vnode *vp, int save, struct ucred *cred,
345 	    struct proc *p, int slpflag, int slptimeo));
346 void 	vattr_null __P((struct vattr *vap));
347 int 	vcount __P((struct vnode *vp));
348 int 	vget __P((struct vnode *vp));
349 void 	vgone __P((struct vnode *vp));
350 void 	vgoneall __P((struct vnode *vp));
351 int	vn_bwrite __P((struct vop_bwrite_args *ap));
352 int 	vn_close __P((struct vnode *vp,
353 	    int flags, struct ucred *cred, struct proc *p));
354 int 	vn_closefile __P((struct file *fp, struct proc *p));
355 int	vn_ioctl __P((struct file *fp, int com, caddr_t data, struct proc *p));
356 int 	vn_open __P((struct nameidata *ndp, int fmode, int cmode));
357 int 	vn_rdwr __P((enum uio_rw rw, struct vnode *vp, caddr_t base,
358 	    int len, off_t offset, enum uio_seg segflg, int ioflg,
359 	    struct ucred *cred, int *aresid, struct proc *p));
360 int	vn_read __P((struct file *fp, struct uio *uio, struct ucred *cred));
361 int	vn_select __P((struct file *fp, int which, struct proc *p));
362 int	vn_stat __P((struct vnode *vp, struct stat *sb, struct proc *p));
363 int	vn_write __P((struct file *fp, struct uio *uio, struct ucred *cred));
364 struct vnode *
365 	checkalias __P((struct vnode *vp, dev_t nvp_rdev, struct mount *mp));
366 void 	vput __P((struct vnode *vp));
367 void 	vref __P((struct vnode *vp));
368 void 	vrele __P((struct vnode *vp));
369 #endif /* KERNEL */
370