FreeBSD/Linux Kernel Cross Reference
sys/sys/lockf.h
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 * 4. Neither the name of the University nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 *
32 * @(#)lockf.h 8.1 (Berkeley) 6/11/93
33 * $FreeBSD: releng/6.0/sys/sys/lockf.h 151755 2005-10-27 18:35:19Z glebius $
34 */
35
36 #ifndef _SYS_LOCKF_H_
37 #define _SYS_LOCKF_H_
38
39 #include <sys/queue.h>
40
41 struct vop_advlock_args;
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 */
49 TAILQ_HEAD(locklist, lockf);
50
51 struct lockf {
52 short lf_flags; /* Semantics: F_POSIX, F_FLOCK, F_WAIT */
53 short lf_type; /* Lock type: F_RDLCK, F_WRLCK */
54 off_t lf_start; /* Byte # of the start of the lock */
55 off_t lf_end; /* Byte # of the end of the lock (-1=EOF) */
56 caddr_t lf_id; /* Id of the resource holding the lock */
57 struct lockf **lf_head; /* Back pointer to the head of the locf list */
58 struct inode *lf_inode; /* Back pointer to the inode */
59 struct lockf *lf_next; /* Pointer to the next lock on this inode */
60 struct locklist lf_blkhd; /* List of requests blocked on this lock */
61 TAILQ_ENTRY(lockf) lf_block;/* A request waiting for a lock */
62 };
63
64 /* Maximum length of sleep chains to traverse to try and detect deadlock. */
65 #define MAXDEPTH 50
66
67 int lf_advlock(struct vop_advlock_args *, struct lockf **, u_quad_t);
68
69 #endif /* !_SYS_LOCKF_H_ */
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