lockf.h revision 33057 
1/*
2 * Copyright (c) 1991, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * Scooter Morris at Genentech Inc.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 *    must display the following acknowledgement:
18 *	This product includes software developed by the University of
19 *	California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 *    may be used to endorse or promote products derived from this software
22 *    without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 *
36 *	@(#)lockf.h	8.1 (Berkeley) 6/11/93
37 * $Id: lockf.h,v 1.8 1997/09/07 05:27:16 bde Exp $
38 */
39
40#ifndef _SYS_LOCKF_H_
41#define	_SYS_LOCKF_H_
42
43#include <sys/queue.h>
44
45struct vop_advlock_args;
46
47/*
48 * The lockf structure is a kernel structure which contains the information
49 * associated with a byte range lock.  The lockf structures are linked into
50 * the inode structure. Locks are sorted by the starting byte of the lock for
51 * efficiency.
52 */
53TAILQ_HEAD(locklist, lockf);
54
55struct lockf {
56	short	lf_flags;	    /* Semantics: F_POSIX, F_FLOCK, F_WAIT */
57	short	lf_type;	    /* Lock type: F_RDLCK, F_WRLCK */
58	off_t	lf_start;	    /* Byte # of the start of the lock */
59	off_t	lf_end;		    /* Byte # of the end of the lock (-1=EOF) */
60	caddr_t	lf_id;		    /* Id of the resource holding the lock */
61	struct	lockf **lf_head;    /* Back pointer to the head of the locf list */
62	struct	inode *lf_inode;    /* Back pointer to the inode */
63	struct	lockf *lf_next;	    /* Pointer to the next lock on this inode */
64	struct	locklist lf_blkhd;  /* List of requests blocked on this lock */
65	TAILQ_ENTRY(lockf) lf_block;/* A request waiting for a lock */
66};
67
68/* Maximum length of sleep chains to traverse to try and detect deadlock. */
69#define MAXDEPTH 50
70
71int	 lf_advlock __P((struct vop_advlock_args *, struct lockf **, u_quad_t));
72
73#ifdef LOCKF_DEBUG
74void	lf_print __P((char *, struct lockf *));
75void	lf_printlist __P((char *, struct lockf *));
76#endif
77
78#endif /* !_SYS_LOCKF_H_ */
79