1 /* $OpenBSD: lockf.h,v 1.7 2005/03/10 17:26:10 tedu Exp $ */
2 /* $NetBSD: lockf.h,v 1.5 1994/06/29 06:44:33 cgd Exp $ */
3
4 /*
5 * Copyright (c) 1991, 1993
6 * The Regents of the University of California. All rights reserved.
7 *
8 * This code is derived from software contributed to Berkeley by
9 * Scooter Morris at Genentech Inc.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. Neither the name of the University nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 *
35 * @(#)lockf.h 8.1 (Berkeley) 6/11/93
36 */
37
38 /*
39 * The lockf structure is a kernel structure which contains the information
40 * associated with a byte range lock. The lockf structures are linked into
41 * the inode structure. Locks are sorted by the starting byte of the lock for
42 * efficiency.
43 */
44 TAILQ_HEAD(locklist, lockf);
45
46 struct lockf {
47 short lf_flags; /* Lock semantics: F_POSIX, F_FLOCK, F_WAIT */
48 short lf_type; /* Lock type: F_RDLCK, F_WRLCK */
49 off_t lf_start; /* The byte # of the start of the lock */
50 off_t lf_end; /* The byte # of the end of the lock (-1=EOF)*/
51 caddr_t lf_id; /* The id of the resource holding the lock */
52 struct lockf **lf_head; /* Back pointer to the head of lockf list */
53 struct lockf *lf_next; /* A pointer to the next lock on this inode */
54 struct locklist lf_blkhd; /* The list of blocked locks */
55 TAILQ_ENTRY(lockf) lf_block; /* A request waiting for a lock */
56 uid_t lf_uid; /* User ID responsible */
57 };
58
59 /* Maximum length of sleep chains to traverse to try and detect deadlock. */
60 #define MAXDEPTH 50
61
62 __BEGIN_DECLS
63 void lf_init(void);
64 int lf_advlock(struct lockf **,
65 off_t, caddr_t, int, struct flock *, int);
66 int lf_clearlock(struct lockf *);
67 int lf_findoverlap(struct lockf *,
68 struct lockf *, int, struct lockf ***, struct lockf **);
69 struct lockf *
70 lf_getblock(struct lockf *);
71 int lf_getlock(struct lockf *, struct flock *);
72 int lf_setlock(struct lockf *);
73 void lf_split(struct lockf *, struct lockf *);
74 void lf_wakelock(struct lockf *);
75 __END_DECLS
76
77 #ifdef LOCKF_DEBUG
78 extern int lockf_debug;
79
80 __BEGIN_DECLS
81 void lf_print(char *, struct lockf *);
82 void lf_printlist(char *, struct lockf *);
83 __END_DECLS
84 #endif