1/*
2 * Copyright (c) 2004-2006 Apple Computer, Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28/*
29 * Copyright (c) 1991, 1993
30 *	The Regents of the University of California.  All rights reserved.
31 *
32 * This code is derived from software contributed to Berkeley by
33 * Scooter Morris at Genentech Inc.
34 *
35 * Redistribution and use in source and binary forms, with or without
36 * modification, are permitted provided that the following conditions
37 * are met:
38 * 1. Redistributions of source code must retain the above copyright
39 *    notice, this list of conditions and the following disclaimer.
40 * 2. Redistributions in binary form must reproduce the above copyright
41 *    notice, this list of conditions and the following disclaimer in the
42 *    documentation and/or other materials provided with the distribution.
43 * 4. Neither the name of the University nor the names of its contributors
44 *    may be used to endorse or promote products derived from this software
45 *    without specific prior written permission.
46 *
47 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
48 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
49 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
50 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
51 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
52 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
53 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
54 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
55 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
56 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
57 * SUCH DAMAGE.
58 *
59 *	@(#)lockf.h	8.1 (Berkeley) 6/11/93
60 * $FreeBSD: src/sys/sys/lockf.h,v 1.16 2004/04/07 04:19:49 imp Exp $
61 */
62
63#ifndef _SYS_LOCKF_H_
64#define	_SYS_LOCKF_H_
65
66#include <sys/queue.h>
67#include <sys/cdefs.h>
68
69struct vnop_advlock_args;
70struct vnode;
71
72#ifdef MALLOC_DECLARE
73MALLOC_DECLARE(M_LOCKF);
74#endif
75
76/*
77 * The lockf structure is a kernel structure which contains the information
78 * associated with a byte range lock.  The lockf structures are linked into
79 * the vnode structure.  Locks are sorted by the starting byte of the lock for
80 * efficiency after they have been committed; uncommitted locks are on the list
81 * head so they may quickly be accessed, and are both short lived and transient.
82 */
83TAILQ_HEAD(locklist, lockf);
84
85#pragma pack(4)
86
87struct lockf {
88	short	lf_flags;	    /* Semantics: F_POSIX, F_FLOCK, F_WAIT */
89	short	lf_type;	 /* Lock type: F_RDLCK, F_WRLCK */
90	off_t	lf_start;	    /* Byte # of the start of the lock */
91	off_t	lf_end;		    /* Byte # of the end of the lock (-1=EOF) */
92	caddr_t	lf_id;		    /* Id of the resource holding the lock */
93	struct	lockf **lf_head;    /* Back pointer to the head of the locf list */
94	struct vnode *lf_vnode;	    /* Back pointer to the inode */
95	struct	lockf *lf_next;	    /* Pointer to the next lock on this inode */
96	struct	locklist lf_blkhd;  /* List of requests blocked on this lock */
97	TAILQ_ENTRY(lockf) lf_block;/* A request waiting for a lock */
98};
99
100#pragma pack()
101
102/* Maximum length of sleep chains to traverse to try and detect deadlock. */
103#define MAXDEPTH 50
104
105__BEGIN_DECLS
106
107#ifdef KERNEL_PRIVATE
108int	lf_advlock(struct vnop_advlock_args *);
109int	lf_assert(struct vnop_advlock_args *, void **);
110void	lf_commit(void *, int);
111void	lf_abort_advlocks(vnode_t);
112
113#ifdef LOCKF_DEBUG
114void	lf_print(char *, struct lockf *);
115void	lf_printlist(char *, struct lockf *);
116#endif
117#endif /* KERNEL_PRIVATE */
118
119__END_DECLS
120
121#endif /* !_SYS_LOCKF_H_ */
122