lockf.h revision 2165 
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 1.1 1994/08/08 17:30:58 davidg Exp $
38 */
39
40#ifndef _SYS_LOCKF_H_
41#define _SYS_LOCKF_H_
42
43/*
44 * The lockf structure is a kernel structure which contains the information
45 * associated with a byte range lock.  The lockf structures are linked into
46 * the inode structure. Locks are sorted by the starting byte of the lock for
47 * efficiency.
48 */
49struct lockf {
50	short	lf_flags;	 /* Lock semantics: F_POSIX, F_FLOCK, F_WAIT */
51	short	lf_type;	 /* Lock type: F_RDLCK, F_WRLCK */
52	off_t	lf_start;	 /* The byte # of the start of the lock */
53	off_t	lf_end;		 /* The byte # of the end of the lock (-1=EOF)*/
54	caddr_t	lf_id;		 /* The id of the resource holding the lock */
55	struct	lockf **lf_head; /* Back pointer to the head of the lockf list */
56	struct	lockf *lf_next;	 /* A pointer to the next lock on this inode */
57	struct	lockf *lf_block; /* The list of blocked locks */
58};
59
60/* Maximum length of sleep chains to traverse to try and detect deadlock. */
61#define MAXDEPTH 50
62
63__BEGIN_DECLS
64int	 lf_advlock __P((struct vop_advlock_args *, struct lockf **, u_quad_t));
65void	 lf_addblock __P((struct lockf *, struct lockf *));
66int	 lf_clearlock __P((struct lockf *));
67int	 lf_findoverlap __P((struct lockf *,
68	    struct lockf *, int, struct lockf ***, struct lockf **));
69struct lockf *
70	 lf_getblock __P((struct lockf *));
71int	 lf_getlock __P((struct lockf *, struct flock *));
72int	 lf_setlock __P((struct lockf *));
73void	 lf_split __P((struct lockf *, struct lockf *));
74void	 lf_wakelock __P((struct lockf *));
75__END_DECLS
76
77#ifdef LOCKF_DEBUG
78extern int lockf_debug;
79
80__BEGIN_DECLS
81void	lf_print __P((char *, struct lockf *));
82void	lf_printlist __P((char *, struct lockf *));
83__END_DECLS
84#endif
85
86#endif
87