vnode.h revision 7945
1/*
2 * Copyright (c) 1989, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 *    must display the following acknowledgement:
15 *	This product includes software developed by the University of
16 *	California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 *	@(#)vnode.h	8.7 (Berkeley) 2/4/94
34 * $Id: vnode.h,v 1.19 1995/04/09 06:03:33 davidg Exp $
35 */
36
37#ifndef _SYS_VNODE_H_
38#define	_SYS_VNODE_H_
39
40#include <sys/queue.h>
41
42/*
43 * The vnode is the focus of all file activity in UNIX.  There is a
44 * unique vnode allocated for each active file, each current directory,
45 * each mounted-on file, text file, and the root.
46 */
47
48/*
49 * Vnode types.  VNON means no type.
50 */
51enum vtype	{ VNON, VREG, VDIR, VBLK, VCHR, VLNK, VSOCK, VFIFO, VBAD };
52
53/*
54 * Vnode tag types.
55 * These are for the benefit of external programs only (e.g., pstat)
56 * and should NEVER be inspected by the kernel.
57 */
58enum vtagtype	{
59	VT_NON, VT_UFS, VT_NFS, VT_MFS, VT_PC, VT_LFS, VT_LOFS, VT_FDESC,
60	VT_PORTAL, VT_NULL, VT_UMAP, VT_KERNFS, VT_PROCFS, VT_AFS, VT_ISOFS,
61	VT_UNION, VT_MSDOSFS, VT_DEVFS
62};
63
64/*
65 * Each underlying filesystem allocates its own private area and hangs
66 * it from v_data.  If non-null, this area is freed in getnewvnode().
67 */
68LIST_HEAD(buflists, buf);
69
70struct vnode {
71	u_long	v_flag;				/* vnode flags (see below) */
72	short	v_usecount;			/* reference count of users */
73	short	v_writecount;			/* reference count of writers */
74	long	v_holdcnt;			/* page & buffer references */
75	daddr_t	v_lastr;			/* last read (read-ahead) */
76	u_long	v_id;				/* capability identifier */
77	struct	mount *v_mount;			/* ptr to vfs we are in */
78	int 	(**v_op)();			/* vnode operations vector */
79	TAILQ_ENTRY(vnode) v_freelist;		/* vnode freelist */
80	LIST_ENTRY(vnode) v_mntvnodes;		/* vnodes for mount point */
81	struct	buflists v_cleanblkhd;		/* clean blocklist head */
82	struct	buflists v_dirtyblkhd;		/* dirty blocklist head */
83	long	v_numoutput;			/* num of writes in progress */
84	enum	vtype v_type;			/* vnode type */
85	union {
86		struct mount	*vu_mountedhere;/* ptr to mounted vfs (VDIR) */
87		struct socket	*vu_socket;	/* unix ipc (VSOCK) */
88		struct specinfo	*vu_specinfo;	/* device (VCHR, VBLK) */
89		struct fifoinfo	*vu_fifoinfo;	/* fifo (VFIFO) */
90	} v_un;
91	struct	nqlease *v_lease;		/* Soft reference to lease */
92	daddr_t	v_lastw;			/* last write (write cluster) */
93	daddr_t	v_cstart;			/* start block of cluster */
94	daddr_t	v_lasta;			/* last allocation */
95	int	v_clen;				/* length of current cluster */
96	int	v_ralen;			/* Read-ahead length */
97	daddr_t	v_maxra;			/* last readahead block */
98	caddr_t	v_vmdata;			/* Place to store VM pager */
99	enum	vtagtype v_tag;			/* type of underlying data */
100	void 	*v_data;			/* private data for fs */
101};
102#define	v_mountedhere	v_un.vu_mountedhere
103#define	v_socket	v_un.vu_socket
104#define	v_specinfo	v_un.vu_specinfo
105#define	v_fifoinfo	v_un.vu_fifoinfo
106
107/*
108 * Vnode flags.
109 */
110#define	VROOT		0x0001	/* root of its file system */
111#define	VTEXT		0x0002	/* vnode is a pure text prototype */
112#define	VSYSTEM		0x0004	/* vnode being used by kernel */
113#define	VXLOCK		0x0100	/* vnode is locked to change underlying type */
114#define	VXWANT		0x0200	/* process is waiting for vnode */
115#define	VBWAIT		0x0400	/* waiting for output to complete */
116#define	VALIASED	0x0800	/* vnode has an alias */
117#define	VDIROP		0x1000	/* LFS: vnode is involved in a directory op */
118#define VVMIO		0x2000	/* VMIO flag */
119#define VNINACT		0x4000  /* LFS: skip ufs_inactive() in lfs_vunref */
120#define VAGE		0x8000	/* Insert vnode at head of free list */
121
122/*
123 * Vnode attributes.  A field value of VNOVAL represents a field whose value
124 * is unavailable (getattr) or which is not to be changed (setattr).
125 */
126struct vattr {
127	enum vtype	va_type;	/* vnode type (for create) */
128	u_short		va_mode;	/* files access mode and type */
129	short		va_nlink;	/* number of references to file */
130	uid_t		va_uid;		/* owner user id */
131	gid_t		va_gid;		/* owner group id */
132	long		va_fsid;	/* file system id (dev for now) */
133	long		va_fileid;	/* file id */
134	u_quad_t	va_size;	/* file size in bytes */
135	long		va_blocksize;	/* blocksize preferred for i/o */
136	struct timespec	va_atime;	/* time of last access */
137	struct timespec	va_mtime;	/* time of last modification */
138	struct timespec	va_ctime;	/* time file changed */
139	u_long		va_gen;		/* generation number of file */
140	u_long		va_flags;	/* flags defined for file */
141	dev_t		va_rdev;	/* device the special file represents */
142	u_quad_t	va_bytes;	/* bytes of disk space held by file */
143	u_quad_t	va_filerev;	/* file modification number */
144	u_int		va_vaflags;	/* operations flags, see below */
145	long		va_spare;	/* remain quad aligned */
146};
147
148/*
149 * Flags for va_cflags.
150 */
151#define	VA_UTIMES_NULL	0x01		/* utimes argument was NULL */
152
153/*
154 * Flags for ioflag.
155 */
156#define	IO_UNIT		0x01		/* do I/O as atomic unit */
157#define	IO_APPEND	0x02		/* append write to end */
158#define	IO_SYNC		0x04		/* do I/O synchronously */
159#define	IO_NODELOCKED	0x08		/* underlying node already locked */
160#define	IO_NDELAY	0x10		/* FNDELAY flag set in file table */
161#define IO_VMIO		0x20		/* data already in VMIO space */
162
163/*
164 *  Modes.  Some values same as Ixxx entries from inode.h for now.
165 */
166#define	VSUID	04000		/* set user id on execution */
167#define	VSGID	02000		/* set group id on execution */
168#define	VSVTX	01000		/* save swapped text even after use */
169#define	VREAD	00400		/* read, write, execute permissions */
170#define	VWRITE	00200
171#define	VEXEC	00100
172
173/*
174 * Token indicating no attribute value yet assigned.
175 */
176#define	VNOVAL	(-1)
177
178#ifdef KERNEL
179/*
180 * Convert between vnode types and inode formats (since POSIX.1
181 * defines mode word of stat structure in terms of inode formats).
182 */
183extern enum vtype	iftovt_tab[];
184extern int		vttoif_tab[];
185#define IFTOVT(mode)	(iftovt_tab[((mode) & S_IFMT) >> 12])
186#define VTTOIF(indx)	(vttoif_tab[(int)(indx)])
187#define MAKEIMODE(indx, mode)	(int)(VTTOIF(indx) | (mode))
188
189/*
190 * Flags to various vnode functions.
191 */
192#define	SKIPSYSTEM	0x0001		/* vflush: skip vnodes marked VSYSTEM */
193#define	FORCECLOSE	0x0002		/* vflush: force file closeure */
194#define	WRITECLOSE	0x0004		/* vflush: only close writeable files */
195#define	DOCLOSE		0x0008		/* vclean: close active files */
196#define	V_SAVE		0x0001		/* vinvalbuf: sync file first */
197#define	V_SAVEMETA	0x0002		/* vinvalbuf: leave indirect blocks */
198
199#ifdef DIAGNOSTIC
200#define	HOLDRELE(vp)	holdrele(vp)
201#define	VATTR_NULL(vap)	vattr_null(vap)
202#define	VHOLD(vp)	vhold(vp)
203#define	VREF(vp)	vref(vp)
204
205void	holdrele __P((struct vnode *));
206void	vhold __P((struct vnode *));
207#else
208#define	HOLDRELE(vp)	(vp)->v_holdcnt--	/* decrease buf or page ref */
209#define	VATTR_NULL(vap)	(*(vap) = va_null)	/* initialize a vattr */
210#define	VHOLD(vp)	(vp)->v_holdcnt++	/* increase buf or page ref */
211#define	VREF(vp)	(vp)->v_usecount++	/* increase reference */
212#endif
213
214#define	NULLVP	((struct vnode *)NULL)
215
216#ifdef VFS_LKM
217#define VNODEOP_SET(f) DATA_SET(MODVNOPS,f)
218#else
219#define VNODEOP_SET(f) DATA_SET(vfs_opv_descs_,f)
220#endif
221
222/*
223 * Global vnode data.
224 */
225extern	struct vnode *rootvnode;	/* root (i.e. "/") vnode */
226extern	int desiredvnodes;		/* number of vnodes desired */
227extern	int prtactive;			/* nonzero to call vprint() */
228extern	struct vattr va_null;		/* predefined null vattr structure */
229
230/*
231 * Macro/function to check for client cache inconsistency w.r.t. leasing.
232 */
233#define	LEASE_READ	0x1		/* Check lease for readers */
234#define	LEASE_WRITE	0x2		/* Check lease for modifiers */
235
236extern void	(*lease_check) __P((struct vnode *vp, struct proc *p,
237				    struct ucred *ucred, int flag));
238extern void	(*lease_updatetime) __P((int deltat));
239
240#ifdef NFS
241#ifdef NQNFS
242#define	LEASE_CHECK(vp, p, cred, flag)	lease_check((vp), (p), (cred), (flag))
243#define	LEASE_UPDATETIME(dt)		lease_updatetime(dt)
244#else
245#define LEASE_CHECK(vp, p, cred, flag)
246#define LEASE_UPDATETIME(dt)
247#endif /* NQNFS */
248#else
249#define LEASE_CHECK(vp, p, cred, flag) \
250	do { if(lease_check) lease_check((vp), (p), (cred), (flag)); } while(0)
251#define LEASE_UPDATETIME(dt) \
252	do { if(lease_updatetime) lease_updatetime(dt); } while(0)
253#endif /* NFS */
254#endif /* KERNEL */
255
256
257/*
258 * Mods for exensibility.
259 */
260
261/*
262 * Flags for vdesc_flags:
263 */
264#define VDESC_MAX_VPS		16
265/* Low order 16 flag bits are reserved for willrele flags for vp arguments. */
266#define VDESC_VP0_WILLRELE	0x0001
267#define VDESC_VP1_WILLRELE	0x0002
268#define VDESC_VP2_WILLRELE	0x0004
269#define VDESC_VP3_WILLRELE	0x0008
270#define VDESC_NOMAP_VPP		0x0100
271#define VDESC_VPP_WILLRELE	0x0200
272
273/*
274 * VDESC_NO_OFFSET is used to identify the end of the offset list
275 * and in places where no such field exists.
276 */
277#define VDESC_NO_OFFSET -1
278
279/*
280 * This structure describes the vnode operation taking place.
281 */
282struct vnodeop_desc {
283	int	vdesc_offset;		/* offset in vector--first for speed */
284	char    *vdesc_name;		/* a readable name for debugging */
285	int	vdesc_flags;		/* VDESC_* flags */
286
287	/*
288	 * These ops are used by bypass routines to map and locate arguments.
289	 * Creds and procs are not needed in bypass routines, but sometimes
290	 * they are useful to (for example) transport layers.
291	 * Nameidata is useful because it has a cred in it.
292	 */
293	int	*vdesc_vp_offsets;	/* list ended by VDESC_NO_OFFSET */
294	int	vdesc_vpp_offset;	/* return vpp location */
295	int	vdesc_cred_offset;	/* cred location, if any */
296	int	vdesc_proc_offset;	/* proc location, if any */
297	int	vdesc_componentname_offset; /* if any */
298	/*
299	 * Finally, we've got a list of private data (about each operation)
300	 * for each transport layer.  (Support to manage this list is not
301	 * yet part of BSD.)
302	 */
303	caddr_t	*vdesc_transports;
304};
305
306#ifdef KERNEL
307/*
308 * A list of all the operation descs.
309 */
310extern struct vnodeop_desc *vnodeop_descs[];
311
312
313/*
314 * This macro is very helpful in defining those offsets in the vdesc struct.
315 *
316 * This is stolen from X11R4.  I ingored all the fancy stuff for
317 * Crays, so if you decide to port this to such a serious machine,
318 * you might want to consult Intrisics.h's XtOffset{,Of,To}.
319 */
320#define VOPARG_OFFSET(p_type,field) \
321        ((int) (((char *) (&(((p_type)NULL)->field))) - ((char *) NULL)))
322#define VOPARG_OFFSETOF(s_type,field) \
323	VOPARG_OFFSET(s_type*,field)
324#define VOPARG_OFFSETTO(S_TYPE,S_OFFSET,STRUCT_P) \
325	((S_TYPE)(((char*)(STRUCT_P))+(S_OFFSET)))
326
327
328/*
329 * This structure is used to configure the new vnodeops vector.
330 */
331struct vnodeopv_entry_desc {
332	struct vnodeop_desc *opve_op;   /* which operation this is */
333	int (*opve_impl)();		/* code implementing this operation */
334};
335struct vnodeopv_desc {
336			/* ptr to the ptr to the vector where op should go */
337	int (***opv_desc_vector_p)();
338	struct vnodeopv_entry_desc *opv_desc_ops;   /* null terminated list */
339};
340
341/*
342 * A default routine which just returns an error.
343 */
344int vn_default_error __P((void));
345
346/*
347 * A generic structure.
348 * This can be used by bypass routines to identify generic arguments.
349 */
350struct vop_generic_args {
351	struct vnodeop_desc *a_desc;
352	/* other random data follows, presumably */
353};
354
355/*
356 * VOCALL calls an op given an ops vector.  We break it out because BSD's
357 * vclean changes the ops vector and then wants to call ops with the old
358 * vector.
359 */
360#define VOCALL(OPSV,OFF,AP) (( *((OPSV)[(OFF)])) (AP))
361
362/*
363 * This call works for vnodes in the kernel.
364 */
365#define VCALL(VP,OFF,AP) VOCALL((VP)->v_op,(OFF),(AP))
366#define VDESC(OP) (& __CONCAT(OP,_desc))
367#define VOFFSET(OP) (VDESC(OP)->vdesc_offset)
368
369/*
370 * Finally, include the default set of vnode operations.
371 */
372#include <vnode_if.h>
373
374/*
375 * Public vnode manipulation functions.
376 */
377struct componentname;
378struct file;
379struct mount;
380struct nameidata;
381struct proc;
382struct stat;
383struct ucred;
384struct uio;
385struct vattr;
386struct vnode;
387struct vop_bwrite_args;
388
389int 	bdevvp __P((dev_t dev, struct vnode **vpp));
390/* cache_* may belong in namei.h. */
391void	cache_enter __P((struct vnode *dvp, struct vnode *vp,
392	    struct componentname *cnp));
393int	cache_lookup __P((struct vnode *dvp, struct vnode **vpp,
394	    struct componentname *cnp));
395void	cache_purge __P((struct vnode *vp));
396void	cache_purgevfs __P((struct mount *mp));
397int 	getnewvnode __P((enum vtagtype tag,
398	    struct mount *mp, int (**vops)(), struct vnode **vpp));
399int	vinvalbuf __P((struct vnode *vp, int save, struct ucred *cred,
400	    struct proc *p, int slpflag, int slptimeo));
401void 	vattr_null __P((struct vattr *vap));
402int 	vcount __P((struct vnode *vp));
403int	vfinddev __P((dev_t dev, enum vtype type, struct vnode **vpp));
404int 	vget __P((struct vnode *vp, int lockflag));
405void 	vgone __P((struct vnode *vp));
406void 	vgoneall __P((struct vnode *vp));
407int	vn_bwrite __P((struct vop_bwrite_args *ap));
408int 	vn_close __P((struct vnode *vp,
409	    int flags, struct ucred *cred, struct proc *p));
410int 	vn_closefile __P((struct file *fp, struct proc *p));
411int	vn_ioctl __P((struct file *fp, int com, caddr_t data, struct proc *p));
412int 	vn_open __P((struct nameidata *ndp, int fmode, int cmode));
413int 	vn_rdwr __P((enum uio_rw rw, struct vnode *vp, caddr_t base,
414	    int len, off_t offset, enum uio_seg segflg, int ioflg,
415	    struct ucred *cred, int *aresid, struct proc *p));
416int	vn_read __P((struct file *fp, struct uio *uio, struct ucred *cred));
417int	vn_select __P((struct file *fp, int which, struct proc *p));
418int	vn_stat __P((struct vnode *vp, struct stat *sb, struct proc *p));
419int	vn_write __P((struct file *fp, struct uio *uio, struct ucred *cred));
420struct vnode *
421	checkalias __P((struct vnode *vp, dev_t nvp_rdev, struct mount *mp));
422void	vprint __P((char *, struct vnode *));
423void 	vput __P((struct vnode *vp));
424void 	vref __P((struct vnode *vp));
425void 	vrele __P((struct vnode *vp));
426int 	vn_writechk __P((struct vnode *vp));
427
428void	vfs_opv_init __P((struct vnodeopv_desc **));
429#endif /* KERNEL */
430
431#endif /* !_SYS_VNODE_H_ */
432