xref: /xnu-11215/bsd/sys/lockf.h (revision 1031c584)
1 /*
2  * Copyright (c) 2004-2018 Apple 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 #include <sys/types.h>
69 
70 struct vnop_advlock_args;
71 struct vnode;
72 
73 #if IMPORTANCE_INHERITANCE
74 #define LF_NOT_BOOSTED  0
75 #define LF_BOOSTED      1
76 #endif /* IMPORTANCE_INHERITANCE */
77 
78 /*
79  * The lockf structure is a kernel structure which contains the information
80  * associated with a byte range lock.  The lockf structures are linked into
81  * the vnode structure.  Locks are sorted by the starting byte of the lock for
82  * efficiency after they have been committed; uncommitted locks are on the list
83  * head so they may quickly be accessed, and are both short lived and transient.
84  */
85 TAILQ_HEAD(locklist, lockf);
86 
87 struct lockf {
88 	short   lf_flags;           /* Semantics: F_POSIX, F_FLOCK, F_WAIT */
89 	short   lf_type;            /* Lock type: F_RDLCK, F_WRLCK */
90 #if IMPORTANCE_INHERITANCE
91 	int     lf_boosted;         /* Is the owner of the lock boosted */
92 #endif
93 	off_t   lf_start;           /* Byte # of the start of the lock */
94 	off_t   lf_end;             /* Byte # of the end of the lock (-1=EOF) */
95 	caddr_t lf_id;              /* Id of the resource holding the lock */
96 	struct  lockf **lf_head;    /* Back pointer to the head of the lockf list */
97 	struct  vnode *lf_vnode;    /* Back pointer to the inode */
98 	struct  lockf *lf_next;     /* Pointer to the next lock on this inode */
99 	struct  locklist lf_blkhd;  /* List of requests blocked on this lock */
100 	TAILQ_ENTRY(lockf) lf_block;/* A request waiting for a lock */
101 	struct  proc *lf_owner;     /* The proc that did the SETLK, if known */
102 };
103 
104 __BEGIN_DECLS
105 
106 #ifdef KERNEL_PRIVATE
107 void    lf_init(void);
108 int     lf_advlock(struct vnop_advlock_args *);
109 int     lf_assert(struct vnop_advlock_args *, void **);
110 void    lf_commit(void *, int);
111 void    lf_abort_advlocks(vnode_t);
112 
113 #ifdef LOCKF_DEBUG
114 void    lf_print(char *, struct lockf *);
115 void    lf_printlist(char *, struct lockf *);
116 #endif
117 #endif /* KERNEL_PRIVATE */
118 
119 __END_DECLS
120 
121 #endif /* !_SYS_LOCKF_H_ */
122