File: [local] / sys / sys / lockf.h (download)
Revision 1.1, Tue Mar 4 16:16:12 2008 UTC (16 years, 2 months ago) by nbrk
Branch point for: MAIN
Initial revision
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/* $OpenBSD: lockf.h,v 1.7 2005/03/10 17:26:10 tedu Exp $ */
/* $NetBSD: lockf.h,v 1.5 1994/06/29 06:44:33 cgd Exp $ */
/*
* Copyright (c) 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Scooter Morris at Genentech Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)lockf.h 8.1 (Berkeley) 6/11/93
*/
/*
* The lockf structure is a kernel structure which contains the information
* associated with a byte range lock. The lockf structures are linked into
* the inode structure. Locks are sorted by the starting byte of the lock for
* efficiency.
*/
TAILQ_HEAD(locklist, lockf);
struct lockf {
short lf_flags; /* Lock semantics: F_POSIX, F_FLOCK, F_WAIT */
short lf_type; /* Lock type: F_RDLCK, F_WRLCK */
off_t lf_start; /* The byte # of the start of the lock */
off_t lf_end; /* The byte # of the end of the lock (-1=EOF)*/
caddr_t lf_id; /* The id of the resource holding the lock */
struct lockf **lf_head; /* Back pointer to the head of lockf list */
struct lockf *lf_next; /* A pointer to the next lock on this inode */
struct locklist lf_blkhd; /* The list of blocked locks */
TAILQ_ENTRY(lockf) lf_block; /* A request waiting for a lock */
uid_t lf_uid; /* User ID responsible */
};
/* Maximum length of sleep chains to traverse to try and detect deadlock. */
#define MAXDEPTH 50
__BEGIN_DECLS
void lf_init(void);
int lf_advlock(struct lockf **,
off_t, caddr_t, int, struct flock *, int);
int lf_clearlock(struct lockf *);
int lf_findoverlap(struct lockf *,
struct lockf *, int, struct lockf ***, struct lockf **);
struct lockf *
lf_getblock(struct lockf *);
int lf_getlock(struct lockf *, struct flock *);
int lf_setlock(struct lockf *);
void lf_split(struct lockf *, struct lockf *);
void lf_wakelock(struct lockf *);
__END_DECLS
#ifdef LOCKF_DEBUG
extern int lockf_debug;
__BEGIN_DECLS
void lf_print(char *, struct lockf *);
void lf_printlist(char *, struct lockf *);
__END_DECLS
#endif